Obestatin does not activate orphan G protein-coupled receptor GPR39

摘要: Abstract Recently, the ligand of orphan G protein-coupled receptor GPR39 has been identified as obestatin, a 23-amino acid peptide derived from ghrelin precursor protein. We used two methods to study possible activation by obestatin: cAMP measurements based on luminescent reporter gene and fluorometric Ca 2+ flux method. The former was similar that reported in original publication Zhang et al. [J.V. Zhang, P.G. Ren, O. Avsian-Kretchmer, C.W. Luo, R. Rauch, C. Klein, Obestatin, encoded gene, opposes ghrelin’s effects food intake, Science 310 (2005) 996–999]. latter method promiscuous well chimaeric G-proteins commonly couple receptors phospholipase C pathway, leads intracellular rise. could, however, not demonstrate obestatin via any these signal transduction pathways. could activate high concentrations Zn , demonstrating cell surface expression functional elicit response. response affected obestatin. identity native for remains be elucidated.